Rare black-footed ferrets released to devour prarie dogs

The U.S government through the U.S. Fish and Wildlife Service is breeding the black-footed ferret in captivity in northern Colorado. Restoring the ferrets, an endangered species, to the United State prairies is considered a key step in to reviving dying ecosystems.

Although the federal government, led by biologists in Colorado, has bred thousands of black-footed ferrets in captivity, they still do not exist as self-sustaining species in the wild.

Plague has attacked some released ferrets in other states, but the bigger problem has been landowners hesitant to allow an endangered animal on their land fearing liability if anything happens to it

Colorado law prohibits any state role introducing endangered species without legislative approval. However, the state law was relaxed this year to let ferrets be released on private land under new “safe-harbor” deals with the U.S. Fish and Wildlife Service.

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It was the first of these deals that led to Wednesday’s release on cattle rancher Gary Walker’s land west of Pueblo.

“I’m elated. I’ve worked for almost two decades trying to get natural predators for prairie dogs back on my ranch,” Walker said.

Ferrets’ elongated bodies and super-sensitive snouts let them slink through tunnels to underground dens while prairie dogs sleep. They clamp their teeth into the prairie dogs’ necks like vampires and squeeze before devouring their prey.

Walker once hired professional sharpshooters to kill hundreds of prairie dogs. “No matter how much shooting you do, they just spread and spread,” he said, adding that he didn’t use poison for fear of killing rabbits and quail.

The release marks a fresh approach to meeting requirements of the Endangered Species Act, which obligates the government to restore listed species to self-sustaining status in the wild. Enlisting private landowners is an approach that holds promise for recovery of other endangered species, said Tim Sullivan, Colorado director of the Nature Conservancy.

Landowners who agree not to deliberately kill or harass ferrets set loose on their property get written assurances that no future regulatory restrictions will be imposed.

“Incidental killing” of ferrets is not considered grounds for prosecution. And federal biologists commit to help landowners control boundaries and combat plague — the main threat to survival of prairie dogs and ferrets. A version of a vaccine developed by the Army after 9/11 is being tested on ferrets.

In 1967, the black-footed ferret was among the first species to be listed as endangered. Outside Colorado, today there are about 400 alive in the wild at 20 experimental sites.

Ending ferrets’ long stint as endangered “is entirely doable,” said Pete Gober, director of the National Black-footed Ferret Conservation Center, the government’s main breeding complex, which is located on grasslands northeast of Fort Collins.

More than 8,000 black-footed ferrets have been raised in captivity since the species was plucked from the brink of extinction. Two of the nation’s six breeding centers are in Colorado — the federal complex near Fort Collins and an off-limits area at the Cheyenne Mountain Zoo in Colorado Springs.

Each captive-bred ferret is conditioned to prepare for a jump from somewhat pampered conditions to the wild.

Newborns are fed prairie-dog meat. Over two months, the ferrets graduate to obstacle courses in pens, with black tubes simulating burrows, where ferrets practice hunting small prairie dogs.

At 4 months old, most race reflexively after big prairie dogs. (The 10 percent of ferrets who refuse to kill are transported to serve as live display animals at a ferret discovery center in Fort Collins.)

Vaccinations against plague are emerging. A Colorado-based nonprofit, Prairie Wildlife Research, has pioneered the capture of prairie dogs and ferrets for shots. Microchips are implanted. Traps loaded with oats and molasses are used to recapture animals for booster shots that increase protection.

Plague and scarce habitat still present huge challenges, Prairie Wildlife Research director Travis Livieri said. Private ranchers may play a lead role, “but public lands also are going to be crucial” for full recovery, Livieri said.

“The world,” he said, “does not end if black-footed ferrets get released onto a landscape.”